scholarly journals Estimation of phenotypic and genetic trends of the growth traits in Lipska and Svrljig sheep

2012 ◽  
Vol 28 (4) ◽  
pp. 743-749
Author(s):  
V. Caro-Petrovic ◽  
M.P. Petrovic ◽  
M.M. Petrovic ◽  
Z. Ilic ◽  
N. Maksimovic ◽  
...  

Some phenotypic and genetic trends on growth traits of lambs are observed. The research implicated lambs of two local breeds of sheep: Lipska (LP) and Svrljig (SV). All lambs were weighed for the first time at birth (BWB), and thereafter, regularly in two-week intervals. On the basis of the results during weighing the body weight (BW) were adjusted to the average age: 30 (BW30), 60 (BW60) and 90 days (BW90). Results of the effect of genotype on growth showed a significant effect on the growth traits. Sex of lambs had a significant effect at birth and very significant effect at 30 days, but had no significant effect on weight at 60 (BW60) and 90 (BW90) days. Birth type had significant effect on the body weight from birth to weaning and the highest body weights were recorded in singles. Phenotypic correlations were positive and very highly significant between the growth traits. Genetic correlations were significant, but not between all observed ages of lambs.

1982 ◽  
Vol 99 (2) ◽  
pp. 277-285 ◽  
Author(s):  
R. A. Guirgis ◽  
E. A. Afifi ◽  
E. S. E. Galal

SUMMARYA study using 1150 lambs to estimate genetic and phenotypic parameters of some weight and fleece traits was carried out on coarse-wool Barki sheep. The weight traits were birth, weaning, yearling weights and daily gains whereas fleece traits included kemp score, staple length and greasy-fleece weight.Heritability estimates of weight traits were within the range 0·25–0·30. Those of fleece traits were 0·16, 0·21 and 0·43. The repeatability estimates of fleece traits were 0·18, 0·38 and 0·53 for staple length, greasy-fleece weight and kemp score respectively.Phenotypic correlations between body weight and fleece traits were mostly positive. Genetic correlations between greasy-fleece weight and body weights were mostly positive and of medium values. Those between kemp score and body weights were mostly negative, ranging from medium-high to high.


1980 ◽  
Vol 30 (2) ◽  
pp. 271-276 ◽  
Author(s):  
A. P. Mavrogenis ◽  
A. Louca ◽  
O. W. Robison

ABSTRACTData on 792 Chios lambs born during the 1972/73 and 1973/74 lambing seasons were used to estimate genetic and phenotypic parameters for birth weight, weaning weight, age at weaning, pre-weaning daily gain, body weight at 5, 10, 15 and 20 weeks of age, and postweaning daily gain. Body weight at 15 weeks of age had the highest heritability estimate (0·73 ± 0·17) and that of post-weaning daily gain was also high (0·56 ± 0·15). Selection for either weight at 15 weeks or post-weaning daily gain would be expected to yield a greater response than selection for pre-weaning daily gain or weaning weight. Genetic correlations among weights and/or gains were positive (approximately 0·20). Phenotypic correlations among weights and gains were generally higher than genetic correlations. However, the correlation between pre— and post-weaning daily gain was small (0·08). Likewise, post-weaning daily gain had low correlations with all weights before 10 weeks. Age at weaning had moderate negative associations with all weights but a very low positive correlation with post-weaning daily gain.


2019 ◽  
Vol 50 (6) ◽  
Author(s):  
Hermiz & Baper

Body weights at birth (469), weaning (394) and at six month of age (358) for kids utilized in this study were raised at private project in Duhok governorate, Iraq during two kidding season (2016-2017) and (2017-2018). GLM within SAS programme was used to analyze the data which include the fixed effects (age of doe, year and season of kidding, sex of kid and type of birth, regression on doe weight at kidding, and the regression of later weights of kids on earlier weights) influencing the studied traits. Restricted Maximum Likelihood Method was used to estimate repeatability, heritability, genetic and phenotypic correlations after adjusting the records for fixed effects. Variance components of random effects were tested for positive definite. Overall mean of weights at birth (BWT), weaning (WWT) and 6 month of age (WT6M) were 2.92, 15.32 and 24.45 kg, respectively. Differences among groups of age of doe in all studied traits were not significant, while year of kidding and sex of kid affect all traits significantly (p<0.01). Season of kidding affect BWT and WWT significantly (P<0.01). Single born kids were heavier (P<0.01) than twins in BWT only. Regression of BWT on doe weight at kidding (0.033 kg/kg) was significant (P<0.01), while the regressions of WWT and WT6M were not significant. The regression coefficients of WWT on BWT (1.906 kg/kg) and of WT6M on WWT (0.835 kg/kg) were highly significant (P<0.01). Repeatability estimates for BWT, WWT and WT6M were 0.47, 0.45 and 0.35, respectively; on the same order the estimates of heritability were 0.41, 0.61 and 0.79. Genetic correlations between BWT with each of WWT (0.45) and WT6M (0.55), and between WWT and WT6M (0.68) were highly significant. All phenotypic correlations between each pair of body weights were higher than genetic correlations and ranged between 0.48 and 0.73.


2013 ◽  
Vol 29 (2) ◽  
pp. 277-286 ◽  
Author(s):  
Zoran Ilic ◽  
A. Jevtic-Vukmirovic ◽  
M.P. Petrovic ◽  
V. Caro-Petrovic ◽  
B. Milosevic ◽  
...  

Estrus synchronization methods was use to control the reproductive traits of sheep, as well as bringing more females at the same stage of estrus and ovulation. According to the points mentioned above, the aim of the present study was to investigate and compare mating method and influence of fixed factors on birth and weaning weight of lambs. Statistical analysis showed that exist difference in the body weights between genotypes of lambs. In the first group, the difference in weight of lambs at birth, regardless of mating method was not significant (P> 0.05), while in the second group, the difference was slightly significant (P <0.05). As for the birth type, sex and within the same genotype, there was a statistical significance (P <0.05) between singles obtained naturally, between the triplets obtained naturally and between triplets received hormonal method. All the differences between body weight at 30 days (mating method, sex and birth type under the same genotype) were statistically significant (P <0.05).The determined differences in the body weights at 60 days (sex, mating method and type of birth under the same genotype) were statistically significant (P <0.05). The results showed that the differences (mating method, sex and type of birth under the same genotype) were statistically significant (P <0.05), except in between body weight at 90 days in twins among two genotypes obtained by natural method, which were not statistically significant (P> 0.05).


1988 ◽  
Vol 110 (1) ◽  
pp. 179-190
Author(s):  
Gh. A. El-Sayiad ◽  
I. F. M. Marai ◽  
E. A. Afifi

SummaryPeking ducklings were classified at 6 weeks of age according to their body weights in two categories: R, below the overall mean of the flock which were considered as retarded growth; and L, those of body weight equal to the overall mean and above which were considered as large. From each group, males and females were chosen to be parents of the next generation in a ratio 1:5 at 6 months of age and four systems of matings were conducted: RR, LL, RL and LR.At all ages studied the large ducklings were significantly heavier than retarded growth ones and had significantly greater body gain, during the two successive generations.The RL and LR matings were heavier than the RR and LL groups at the different ages studied, indicating an effect of heterosis and that the retarded growth character is controlled by few pairs of genes. The differences due to mating systems were not significant either in body weight or body gain, except in body weight at 18 and 24 weeks and relative gain at 6 weeks of age in which the differences were significant (P <0·05) in the second generation.The other environmental factors studied were sex, month of hatch and 6-week body weight.Heritability estimates were 0·489, 0·509, 0·576, 0·346, 0·713, 0·809, 0·651 and 0·386 for body weight at hatch 4, 6, 8, 12, 16, 18 and 24 weeks of age, respectively, using the data which were adjusted for the effects of sex, month of hatch, 6-week body weight and mating system. The same estimates were 0·482, 0·554, 0·578, 0·352, 0·713, 0·808, 0·650 and 0·386, respectively, using the same data but adjusted for month of hatch and sex only.Phenotypic and genetic correlations between body weights at different ages for the two sets of data were estimated. The phenotypic correlations were negative between body weight at hatch and each of the body weights at 16 and 18 weeks of age for the two corrected sets of data. The genetic correlations were negative between hatch weight and each of the other body weights for the two adjusted sets of data and between body weight at 4 weeks of age and each of the body weights at 16, 18 and 24 weeks only for the first set of data. Phenotypic and genetic correlations between the body weights in older birds were highly positive.


2011 ◽  
Vol 51 (No. 2) ◽  
pp. 54-60 ◽  
Author(s):  
J. Kuchtík ◽  
IDobeš

The effect of some factors (genotype, sex, litter size, age of dam at lambing, month of lambing and year of birth of lamb) on the growth of lambs &ndash; crossbreds between the Improved Wallachian (IW) and East Friesian (EF) breed was evaluated in operating conditions during two successive years. Three genotypes were evaluated: IW 50 EF 50, EF 75 IW 25 and EF 87.5 IW 12.5. The evaluation of the effect of genotype on growth showed that this factor did not have a significant effect on the majority of growth traits under study. In the period from birth to 100 days of age the highest daily gain was found in IW 50 EF 50 (263 g). The daily gains of EF 75 IW 25 and EF&nbsp;87.5 IW 12.5 in this period were lower but identical (244 g). Age of dam had a significant effect on the majority of growth traits under study. Sex of lamb had a significant effect on body weight at 100 days of age and also on the majority of daily gains under study. The factors litter size, month of lambing and year of lamb birth were the most significant sources of variation of daily gains. As far as the non-genetic factors were concerned, the highest daily gains from birth to 100 days of age were recorded in males (259 g), in singles (260 g), in lambs from 4-years-old ewes (269 g), in lambs born in January (263 g) and in lambs born in the first year of evaluation (256 g). The analysis of phenotypic correlations indicated that body weight at birth showed a positive and highly significant (P&nbsp;&le; 0.01) effect on the majority of growth traits under study. All phenotypic correlations between individual body weights were positive and high (P &le; 0.01). The majority of phenotypic correlations between individual daily gains under study were also positive and high (P &le; 0.01). &nbsp;


2010 ◽  
Vol 148 (3) ◽  
pp. 363-370 ◽  
Author(s):  
N. GHAVI HOSSEIN-ZADEH ◽  
M. ARDALAN

SUMMARYThe objective of the present study was to estimate genetic parameters for body weights at different ages and litter size (LS) in Moghani sheep. Traits included were birth weight (BW), 3 months weight (3MW), 6 months weight (6MW), 9 months weight (9MW), yearling weight (YW) and LS. The data of 6659 lambing records and pedigree information used in the current programme were collected at the Breeding Station of Moghani sheep (Ardebil province, Iran) during 1987–2005. Different linear and threshold animal models with additive genetic, maternal genetic, maternal permanent environmental and residual effects were implemented by Gibbs sampling (GS) methodology. A single GS chain with 150 000 rounds was generated by the MTGSAM program. The posterior means of genetic parameters were estimated based on the 1300 samples that were left after elimination of 20 000 rounds in the burn-in period and 100 rounds of each thinning interval. Posterior mean estimates of direct heritability were 0·29, 0·13, 0·14, 0·10, 0·31 and 0·10, while those of maternal heritabilities were 0·29, 0·08, 0·11, 0·06, 0·10 and 0·17 for BW, 3MW, 6MW, 9MW, YW and LS, respectively. Genetic correlations among the growth traits and LS were negative for direct genetic and maternal genetic effects. Therefore, selection for increased growth or LS may have a negative genetic effect on the other traits. The medium to high negative estimates of direct–maternal correlations for body weight traits or LS suggest that it would be difficult to improve direct and maternal growth ability jointly for Moghani sheep.


2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Hermiz & Abdullah

This study aimed to investigate the genetic parameters for body weights of White and Black local chickens. The experiment conducted at College of Agric., Salahaddien Univ. during the period from Sept. 2016 until April 2018. 520 fertile eggs were taken from Agri. Res. Center, Ministry of Agric., Baghdad. Hatched chicks considered as parents (G0), and distributed randomly in to ten families. Resulted eggs from each family were collected during the peak of production for each generation to produce chicks of the next generation (G1 and G2). Body weights of resulted chicks were recorded at 1-day old and weekly till maturity. SAS program used to analyze the body weights (BW) and body weight gains (BWG) at different ages. The model includes genetic groups and generations for traits before sexing and the effect of sex added for the traits after sexing. Variance component of random effects estimated by REML and tested for positive definiteness to develop reliable estimates. Repeatability for body weights estimated. BW of chicks at 1 day, 4, 8, 9, 10, 16 and 17 week were 31.02, 292.47, 679.29, 794.58, 892.82, 1362.53 and 1252.17 g, and BWG at (1-4, 4-8, 9-10 and10-16) weeks were 261.45, 386.82, 98.24, and 469.51 g, respectively. The chicks of black group significantly excelled the white group in their weight at 1 day, 4, 8, 16 and 17, as well at ages 1-4 and 10-16 weeks. The effect of generation on BW of chicks at all ages and BWG at 1-4, 4-8 weeks was highly significant and (P<0.05) during 9-10 and 10-16 weeks. Males surpassed females significantly (p<0.01) in their BW at 9, 10 and 16 weeks and in their BWG during 9-10 and 10-16 weeks. Estimates of heritability were 0.42, 0.61, 0.76, 0.71, 0.43, 0.51, and 0.70 and of repeatability were 0.29, 0.26, 0.22, 0.38, 0.41, 0.74, and 0.78 for BW at 1 day, 4, 8, 9, 10, 16 and 17 weeks respectively. Higher (0.78) and lower (0.14) genetic correlations were recorded between BW at 8 weeks with each of BW at 10 and 17 weeks respectively. While the phenotypic correlations ranged between 0.04 (among BW at 1 day with weight at 9 weeks) and 0.58 (among BW 16 with 17 weeks).


2018 ◽  
Vol 34 (4) ◽  
pp. 433-441
Author(s):  
Houari Yerou ◽  
Hakim Ouldouelhadj ◽  
Abdelrahmane Berber ◽  
Amine Mokadem ◽  
Bachir Koudad

The data base for body weights and growths of 411 Hamra lambs were used to estimate genetic parameters. These lambs were obtained from 31 rams and 493 ewes between 2012 and 2017. Traits analysed were weights at birth (BW), 30 days (W30), 90 days (W90) of age, and average daily gains from 10 to 30 (ADG10-30) and30-90 (ADG30-90) days. REML estimates of variance and covariance components were obtained assuming animal models that included the fixed effects for year-type of birth (2012 single, 2012 twin, . ., 2017 single, 2017 twin), sex (male, female), and ewes age at lambing (< 18, 18-30, 30-42, 42-54, >54 months). Heritabilities were 0.12, 0.06 and 0.11 respectively for BW, W3Oand W90and the average daily gains were 0.05 and 0.17 for ADG0-30and ADG30-90. The estimates of genetic correlations showed no genetic antagonisms among the growth traits. The genetic correlations estimated were positive and medium to high, except those between ADG30-90 and ADG0-30 and between ADG30-90 and W30 which were slightly negative. Phenotypic correlations were positive and ranged from 0.12 to 0.85. They were high between adjacent weights and between ADG and their corresponding weights.


2020 ◽  
Vol 46 (5) ◽  
pp. 28-33
Author(s):  
A. A. Adeoye ◽  
J. E. Udoh ◽  
A. D. Oladepo

One- hundred and twenty-four (124) Nigerian local turkeys at six months of age were used for this study. The turkeys were raised from day old in a commercial farm located at Ibadan and data were collected on growth traits to determine the effect of sex and phenotypic correlations among growth traits. Highest coefficient of variation was observed in body weight in both male (9.95 %) and female (15.74 %) while the least (5.71%) was observed for wing span in female and 4.95% for body length in male. Sex had significant effect (p<0.05) on all the variables in favour of male. The body weight, shank length, thigh length, body length, wing length, wing span and breast girth for males were 3.80 kg, 9.01 cm, 21.68 cm, 63.00 cm, 32.44 cm, 72.86 cm and 40.17 cm, respectively, while the corresponding values for female were 2.93 kg, 7.27 cm, 17.96 cm, 55.37 cm, 28.18 cm, 63.92 cm and 36.14 cm. The correlation coefficients between body weight and the linear measurements in the two sexes were positive and mostly significant in male. It ranged between 0.291 and 0.561 in male and 0.233 and 0.721 in female. Sexual dimorphism was obvious in all the traits considered in favour of male. The positive correlations between body weight and the linear body measurements in the two sexes means improvement in any of the traits will lead to improvement in the body weight.


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